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For more from Chase and Jason, check out their work at Football Perspective and The Big Lead.
ShareThisThrow out the records
I've heard it said that, since teams in the same division know each other well and always have incentive regardless of record, in-division games tend to be closer than out-of-division matchups.
Here is a data dump from which you can draw your own conclusions. This includes all games since the merger from week 6 through the end of the regular season.
DIFF is the number of games that separated the two teams in the standings at the time the game was played. For instance, when the Colts and Texans met last Sunday, the Colts were 11-3 and the Texans were 4-10, making the DIFF 7.
All numbers are presented from the vantage point of the team with the better record. In the DIFF 7 column, for instance, you can see that intradivision games are won by the team with the better record 80.4% of the time while interdivision games are won by the team with the better record 87% of the time.
=== interdivision =====|=== intradivision =====
DIFF N Win% AvMargin N Win% AvMargin
======================================================
0.5 151 0.500 0.4 101 0.520 0.4
1.0 693 0.541 2.1 568 0.547 1.7
1.5 116 0.591 3.4 88 0.523 1.2
2.0 523 0.602 3.5 474 0.560 2.3
2.5 89 0.669 5.0 75 0.653 4.5
3.0 382 0.666 5.2 338 0.660 5.5
3.5 39 0.667 3.3 48 0.708 8.4
4.0 253 0.644 5.9 257 0.716 7.2
4.5 27 0.667 9.1 29 0.828 13.6
5.0 137 0.737 8.8 140 0.707 6.5
5.5 15 0.933 18.1 18 0.944 13.5
6.0 88 0.807 10.0 90 0.767 9.2
6.5 5 0.600 10.0 4 1.000 15.5
7.0 46 0.870 12.4 56 0.804 10.3
7.5 3 0.667 16.0 1 1.000 16.0
8.0 20 0.700 8.5 29 0.897 13.0
8.5 2 1.000 18.5 2 1.000 22.0
9.0 9 0.778 17.1 8 0.875 16.2
9.5 0 0.000 0.0 1 1.000 9.0
10.0 4 0.750 22.0 4 0.750 15.5
10.5 1 1.000 1.0 1 1.000 10.0
11.0 2 1.000 8.5 1 1.000 28.0
This entry was posted on Tuesday, December 26th, 2006 at 6:45 am and is filed under General. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.
My quick glance shows the numbers to be pretty similar and randomly distributed, with lots of bumps in the data for both categories. I don't think there's any significant evidence to point to the "throw out the records" theory.
I agree with Jet fan Chase. I don't think familiarity is a big factor in the NFL. With the ubiquitous nature of game film, scouting, injury reporting requirements, proliferation of numerical data, the above board availability of every game on tv, the fact that there is one set of games a week, and the fact that just avout everybody knows everything about every team, I think the NFL offers its teams as close as you can get to PERFECT INFORMATION about any possible opponent any week. Also, football is football. It is not as if games routinely come down to who tricked who more. It's a fairly straight forward game. Also, how much better do division foes know each other? Best case scenario, they played one previous time in the season. In today's NFL, there is enough turnover on rosters and coaching staffs that I just doubt familiarity means much.
Also, these guys are pros. Fans might get emotional about hating a rival, but players generally view all games as must-win games. Maybe I'm naive, but I doubt teams "try harder" against some teams than against others. Also, you can win your division without dominating it. If you're 10-0 outside your division and 0-6 in it, you still have a good shot at winning the crown.
Division games are pretty much just hype. Any team must simply have a better record than just 3 other teams in the whole league in order to get an automatic playoff game at home. Instead of throwing out the records, throw out the alignment. Have one pool of 32 teams, each playing 16 different opponents each season, without regard to any sort of alignment.. that's what I'd like. (Actually, I'd love a 31 week round robin, but we all know I'm crazy!)
===
Congrats, Chase.... enjoy being alive in wk 17
Not to pick bones but if you go 0-6 in your division I do not think that you have a good shot at winning the division even if you do go 10-0 outside of your division. I would say that you have a pretty poor shot at it. If you lost all 6 division games then the top division team won at least 4 division games (It would be all 3 other teams) and more likely one team won 5 or 6 division games. If the rest of the division goes 4-2 in division then that means that just 1 of the 3 division foes would have to go 6-4 out of division to win the division. Assuming that one team went 5-1 in division then they would just have to be .500 out of division.
Basically what I am saying is that division games are worth way more then other games and teams definitely try harder in division games. Player and Coach turnover may be pretty common but teams are still in similar systems and have similar strengths year to year. And lastly, game film does not equal actually playing a team.
Alright... I'll grant you that the recipe for success in winning one's division doesn't recommend being 0-6 in your division. But, you can go 10-0 outside of it, and there is nothing your division foes can do about that. If you win any division games at all, it adds to that. You seldom need to be 15-1 to win a division. Conversely (or is it inversely), you can go 6-0 in your division and not win it. I don't buy the divisional hype. As to your last point:
Is this gospel or opinion? Is it up for debate? Is it undisputible?
"teams definitely try harder in division games."
Yes, but this doesn't mean that the games should be closer. Say team A is 7 points better than the average team, and team B is 7 points worse than average. You would expect team A to win, on average, by 14 points. Now, say they are in the same division. If both team A and team B "try harder" during that game, and play at a level 3 points better than before, team A will still win, on average by 14 points. The scoring margin shouldn't be any different, and the data show that the scoring margin isn't significantly different in division games.
I agree with you Alex. There is no change because in division games both teams try harder. I would suppose that this would make the better team even more favored to win but the data does not support that.
And Bill M, I am giving my opinion that playing a team gives you a better picture of their plays, formations and weaknesses then watching film. You are free to argue with that.
OK... gotcha
Could we get a total for each column (inter- and intra-divisional)? Yeah, I could probably multiply percentages by # of games and figure it out, but I'm sure you could compile it much quicker
Yea, so Detroit should do well vs Green Bay in week 15. Is that what this is saying?
I've been compiling my own rankings the past 2 seasons, and I think mine are better than Sagarins... I call them "Triple Averages". Have a look.
1...SD...24.35546938
2...Chi...23.96714744
3...Bal...21.90945513
4...NE...20.58365385
5...NO...19.92035256
6...Jac...19.90400641
7...Dal...18.81450961
8...Cin...18.69914364
9...Phi...17.93520763
10...Pit...17.83438358
11...Ind...17.40272436
12...Den...15.9754403
13...KC...15.51074487
14...NYJ...15.26886411
15...Buf...15.00177735
16...Atl...14.48586201
17...StL...14.47483974
18...Mia...14.27193408
19...NYG...14.01017935
20...Sea...14.00242365
21...Min...13.26137821
22...Car...12.50105025
23...Ten...12.32660256
24...Ari...12.0449184
25...Was...11.67296817
26...GB...11.42227564
27...SF...11.32019231
28...Hou...10.24285022
29...TB...10.17999677
30...Det...9.892551301
31...Cle...9.821794872
32...Oak...8.866375828
I don't know if this will help or not, but there are division games and then there are rivalry division games.
As a Broncos fan I know that Raiders week is a little more emotional due to the history there. But San Diego always seems to be just a regular game.
Still that 7% difference seems to be a significant, but is it statistically?
Why are you using "record at the time the game was played"? That seems extremely odd - you're using it as a proxy for team strength in some sense, but the early-season games haven't had time to separate them yet. Just seems like you're going to heavily pollute the data set - a team that's 0-3 vs a team that's 3-0 is being treated the same as a 15-0 team vs a 12-3 team.
Why not just use "record from the end of the season"? Yes, you lose any possibility of evolution of team strength over the season (i.e. if a team's 6-2 and then goes 2-6) but given the quantization early in the season, I don't think it gives you any advantage anyway.
Why are you using "record at the time the game was played"? That seems extremely odd - you're using it as a proxy for team strength in some sense, but the early-season games haven't had time to separate them yet. Just seems like you're going to heavily pollute the data set - a team that's 0-6 vs a team that's 6-0 is being treated the same as a 15-0 team vs a 9-6 team.
Why not just use "record from the end of the season"? Yes, you lose any possibility of evolution of team strength over the season (i.e. if a team's 6-2 and then goes 2-6) but given the quantization early in the season (the first few weeks can't even populate the last bins), I don't think it gives you any advantage anyway. Later in the year, you're just using full-season numbers anyway, so why not use the same thing for the entire year?